Transmission-line device



-NOV.'22, 1932., 5 FLEMING 1,888,715

TRANSMISSION LINE DEVICE- Filed Nov 26 1930 INVENTOR Theodore B. F [6177172 ATTORNEY y aw the clearance between an 1 Patented Nov. 22, 19,32

UNITED STATES PATENT OFFICE THEODORE B. FLEMING, 0F LATBOBE, PENNSYLVANIA, ASSIGNOB '10 WESTINGHOUSE ELECTRIC MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA TRANSMISSION-LINE DEVICE Application filed November 26, 1930. Serial No.

Another object of invention is to provide an electrostatic-field-control element of usual form, such as the so-called arcing ring, that shall be of substantially reduced radius. Another object of my invention is to control the electrostatic field of an insulator in accordance with the direction of the wind or other fluid medium in which the insulator is disposed.

Another object of my invention is to provide an electrostatic-field-control device for a transmission-line insulator that shall be automatically adjustable to compensate for certain conditions.

Another object of my invention is toimprove the field-control structure for atransmission-line insulator, by the inclusion of a ball-bearing device, an extension element and a wind-vane or equivalent features.

Another object of my invention is to reduce sulator field-control element and the supporting tower therefor, to reduce the weight of material employed and to permit the element to vibrate more freely with the line conductor.

-Another objectof my invention is to ensure the occurrence of flashover to the leeward of, and to prevent arms from being blown into, an insulator.

A further object of my invention is to provide a transmission-line, electrostatic-fieldcontrol device that shall be simple and durable in construction, economical to manufacture and effective in its operation.

In the support of high-voltage transmission-line cables, it has been usual to employ a series of flexibly-connected suspension insulators of the cap-and-pin type, and so-called arcing rings adjacent to the terminals of the string of insulators.

Arcing-rings, asheretofore,employed,mustly sixty per greater clearance between the be of certain diameter to prevent cascading between the metal caps and pins of the insulator units; the diameter being substantialcent of the length of the insulator string, and the minimum diameter being substantially forty per cent of the length of the insulator string.

The rings are provided not only to prevent cascading, as pointed out, but also to ensure that fiashover shall occur along a path parallel to the insulator string and spaced therefrom. Without this protection, the insulators are likely to be damaged by power arcs.

The rings increase the lateral space occupied by the insulated string and necessitate string and the supporting transmission-line tower. The lat ter, an already expensive structure, must therefore be larger and, accordingly, more expensive, if rings of the ordinary or usual size and type are to be employed.

The rings of the usual type and size must be of a certain weight to render them selfsustaining under vibration stresses set up by the line cable. They do not respond readily to these stresses and are, therefore, subject to damage or distortion.

Further, under the influence of air currents, an are forming between the rings to the windward of the insulator may be blown into the latter, thereby nullifying the advantage of the rings and causing damage to the insulators.

Accordingly, in practicing my invention, I provide means, such as an electrostatic-fieldcontrol element in the form of a wind-vane, at an intermediate part of the insulator, whereby the rings may be of substantially reduced size and cost, the are may be prevented from blowing into the insulator, and other advantages are obtained, as will be apparent from the following description, considered in the light of the accompanying drawing, wherein:

Figure 1 is a view, in side elevation, of a transmission-line device embodying my invention,

Fig. 2 is an enlarged, detail view, partially in section and partially in side elevation,

f mo a windvane arc-control element shown in Fi 1,

ig. 3 is a view, to Fig. 2, and

ig. 4 is a view, in side elevation, of a por tion of the structure shown in Fig. 2.

The device comprises, in general, a main support 2, an insulator 4, upper and lower electrostatic-field-control rings 6 and 8, respectively, an intermediate electrostatic field-control element 10 and a clamp 12 for supporting an electrically conducting cable 14.

The main support 2 may be the cross arm of a pole or tower and includes a pin 16 to which the insulator 4 is movably attached in a usual manner.

The insulator 4 comprises a string of insulator units of the cap-and-pin type, each of which includes a metallic cap, having a socket therein, and a pin depending therefrom for cooperation, respectively, with the pin and socket of adjacent insulator units, for effecting a flexible connectionbetween the units of the string. One of the cap-and-pin connectors may be modified, as hereinafter described, for supporting the field control element 10. The insulator may, of course, be of the pillar type, or other types, Within the scope of the present invention.

The elements 6 and 8 are constructed of strap-metal, or the like, preferably in the form of rings or loops, and are suitably secured, respectively, to the metal cap of the upper insulator unit of the string and to a link 5 at the lower end of the insulator string. The elements 6 and 8 may be of circular, oval or other contour in plan view, and of plane, crescent or other contour in elevation, or of any other suitable shape.

he element 10 comprises a combined electrostatic-field-control and weather-vane porits outer end, a supporting structure 20 at its inner end, and an arm 22 extending between the vane and the supporting structure.

The field-control vane 18 ,may be of any suitable construction, but as shown for purpose of illustration only, comprises pressed sheet-metal halves 24 of shallow substantially in elevation, at right angles cup-shape having complementary collar por- 22 by pins 28 and tions 26 secured to the arm having a rounded perimeter 30. The vane is preferably shaped to have parallel flat sides normal to the planes of the rings 6 and 8, or otherwise constructed to readily respond to the direction of the wind.

The supporting structure 20, shown more clearly in Figs. 2 and 4, comprises a central link or support having an end socket portion 32, similar to the sockets on the caps of the component insulator units, for attachment to the ball-headed pin of one of the units, and a ball-headed end 34, similar to the pins of the units, for attachment to the socket porelements, or arcing tion of one of the units. The link has ball-race portions 36 and 38, or the reception of ball-bearings, and an overhanging weather-protective canopy portion 40.

cooperating movable bearing element comprises halves 42 and 44 secured to each other, as by bolts 46, having cooperating ballrace portions. The portion 44 is'provided with a socket 48 in which the arm 22' is secured, as by a pin 50.

The clamp 12 is of any suitable construction, such as one comprising a cable-receiving channel member'52, a clamping shoe 54 and bolts 56 for clamping the members 52 and 54 against the conductor 14. The shoe 54 may be provided with a socket portion 58 for the attachment to the link 5 which also has a socket portion 60 for attachment to the pin of the bottom insulator unit.

referably In operation, the wind or fluid-actuated vane 18 is automatically moved about the axis of the insulator 4 in accordance with the direction of the wind, to thereby always be in a position to the leeward of the insulator. Being of conducting material, the vane shortens the eflective air gap between the rings 6 and 8, so that a fiashover, when it oc curs and takes the path of least resistance passes from one of the rings to the field-control element 18, and. from the latter, to the other ring. A short are is more difiicult to displace by wind pressure than a long are, and, since the arc in this instance is not only to the leeward of the insulator but is also divided into two shorter arcs, it will not be blown into the insulator under violent wind conditions.

Also, by reason of the practical assurance 1 of substantially less radial dimensions than prior-art devices of the same general nature.

The transverse radii of the elements 6 and 8, while they must be substantial to have the are safety clear the insulator, may, nevertheless, be substantially less than the minimum radii'of the length of the insulators in former devices. Thus, the rings 6 and 8 may have radii of approximately ten percent and diameters of approximately twenty percent of the insulator length.

In view of the above recited conditions, and since the element 18 may be comparatively small. light in weight and economical in construction. there is not only a substantial saving in weight and materials of the elements 6 and 8 but also, in the main supporting towers an d cross arms, with the attending advantage of more certain and eiiective operation at all times.

While I have shown and described a particular form of my invention, various modifications in the structure and combination of the parts. such as the provision of more than one wind-vane betweenthe ends of the insulator or the substitution of vanes or other elements for the rings may be effected without departing from t e spirit and scope of the invention, as set forth in the appended claims.

I claim as my invention:

1. In combination, an insulator and an electrostatic-field control element mounted to move about the axis thereof.

1o 2. In combination, an insulator and an electrostatic-field-control element disposed between the ends "thereof and mounted to move automatically in reverse directions relative to the insulator.

3. In combination, an insulator and an electro-static-field-control element in the form of a wind-vane mounted for movement relative thereto.

4. In combination, an insulator and an electrostatic-field-control element in the form of a wind-vane disposed intermediate the ends thereof and mounted for movement relative thereto.

5. In combination, a suspension insulator including a plurality of flexibly-connected series units of the cap-and-pin type, an elec; trostatic-field-control element and means for mounting said element including a member constituting a link between a pair of said units having end portions for flexible connection, one to the cap and one to the pin, respectively, of the units of said pair, said element being movably mounted on said link.

6. In combination, an insulator, a com.-

bined wind-vane and electrostatic-field-control element extending radially to the axis thereof, and cooperating stationary and movable bearingmembers connected with the insulator and said element, respectively, rendering the element movable about said axis.

In testimony whereof, I have hereunto sub scribed my name this nineteenth day of November 1930.

THEODORE B. FLEMING. 

